1. Field of the Invention
The present invention relates to an apparatus for a Point-of-Sale (POS) system where the peripheral input devices are connected to a communications port of a general purpose personal computer.
More specifically, the present invention relates to an improved Point-of-Sale (POS) system utilizing a conventional computer and wherein all peripheral input devices are connected in a daisy chain configuration and can be easily inserted or removed from the system.
2. Description of the Prior Art
In the past, most point-of-sale (POS) systems were integrated or xe2x80x9cclosedxe2x80x9d systems where the failure of any one element would require the entire system to be shut down for replacement of the defective element or in the more serious case, the entire system would need to be replaced. These xe2x80x9cclosedxe2x80x9d systems utilize input devicexe2x80x9csimilar to those of the present invention. Typical peripheral input devices are bar code readers, credit card readers, i.e. magnetic stripe readers, POS keypads, electronic scales, etc. Moreover, these computers and peripheral devices were designed as dedicated systems so that generic, off the shelf components could not be utilized as replacements.
In general, different input devices have different interface requirements. Thus input device #1 may be directly connected to the computer keyboard port while input device #2 may require an interface box or circuit to convert its built-in output data format to RS232 data format. Other input devices may require an internal interface card to convert their built-in output format to a data format that is compatible with the computer. The major problems associated with this type of traditional interface are: 1) Each input device requires a hardware interface card or box; and, 2) Each input device requires a software identification number and interrupt number for the computer to address and communicate with the device. As a result, higher hardware costs and more physical space is required as each input device is added to the system. In addition, the added software requirement for each input device requires software changes to be made every time an input device is changed.
In addition to the above-mentioned short falls of the conventional xe2x80x9cclosedxe2x80x9d system, should a particular input device become outdated or obsolete, the entire system will require changing in order to support the new input device. Thus, updating xe2x80x9cclosedxe2x80x9d systems is wasteful, impractical and uneconomical. Moreover, updating closed systems often causes useful and operating components of the system to be replaced when they are still functional but can only be used with the integrated system.
Conventionally, a typical desk top personal computer has two RS232 communications ports and a lap top computer has only one RS232 port. With the addition of a special plug-in card, a personal computer may be expanded to support up to four RS232 ports. Recently, a new interface called the Universal Serial Bus (USB) has been adopted by the personal computer industry. However, the USB has several drawbacks, including:
(1) non-compatibility with the current RS232 standard, both in hardware and in software; and
(2) in order to support more than one peripheral USB device, an expensive hub is required. Moreover, each hub can only drive four USB devices.
Accordingly, there remains a need in the field of point-of-sale systems for an alternative connection configuration which allows a plurality of peripheral input devices to efficiently communicate with a general purpose computer.
It is therefore a goal of one embodiment of the present invention to provide an efficient and flexible point-of-sale (POS) system, which allows peripheral input devices to be freely integrated with or removed from the POS system.
It is a another goal of the present invention to provide a point-of-sale system which allows an unlimited number of peripheral input devices, interconnected in a serial daisy chain configuration, to be coupled to and communicate with a general purpose computer.
It is another purpose of another embodiment of the present invention to provide a point-of-sale system which utilizes an active electronic interface for coupling the input devices to the general purpose computer.
It is yet another goal of one embodiment of the present invention to provide a point-of-sale system whereby peripheral input devices, such as optical scanners, credit card readers, POS keyboards, electronic scales, etc., can be easily inserted or removed from the system without shutting down the computer or reconfiguring the system software or hardware, thereby reducing system down-time.
It is still a further goal of one embodiment of the present invention to provide a point-of-sale system where the failure of one or more peripheral input devices will not impede the operation of the system or other input devices.
The foregoing needs, purposes and goals are satisfied in accordance with the present invention which, in one embodiment, provides a point-of-sale (POS) system including a general purpose computer capable of running applications software for controlling the POS system and having a communications port, such as a keyboard, RS232, Universal Serial Bus (USB), parallel port, or any other suitable port for transferring data. The POS system further includes a plurality of peripheral input devices, interconnected in a serial daisy chain configuration and coupled to the communications port of the computer.
Preferably, each input device has a built-in electronic wedge interface operatively connecting the peripheral device to either the computer communications port or to another peripheral device. A multiplexer included in the wedge interface selectively provides a pass-through connection, whereby other devices connected to the interface can freely transfer data to the computer, or the multiplexer may electrically disconnect peripheral devices connected to the wedge and allow the corresponding peripheral device to communicate with the computer. The wedge interface further includes electronic circuitry which converts the data format of the corresponding peripheral device into a data format compatible with the computer.
In a preferred embodiment in accordance with the present invention, all peripheral input devices are connected, in a daisy chain configuration, to a keyboard input port of a general purpose computer. Each input device has a built-in electronic wedge interface for keyboard device emulation. Each of these input devices can be used singly with the computer, or with other input devices. Since all input data appear to the computer keyboard port as keyboard data, no software changes are required as input devices are added or deleted. Moreover, no additional computer interface cards are required to support additional peripheral input devices. Thus, the components of the system of the present invention can be easily updated or removed from the system without disturbing the other components of the system.
In an alternative embodiment of the present invention, the peripheral input devices are connected in a daisy chain configuration to an RS232 port of the general purpose computer. Each input device has a built-in electronic wedge interface which converts the data format of the peripheral input device to RS232 format for compatibility with the RS232 port of the computer.
Still a further preferred embodiment of the present invention provides an apparatus for serially connecting a plurality of peripheral input devices to a communications port of a general purpose computer. The host computer includes a computer executable software program for controlling a first interface, a second interface and a plurality of corresponding peripheral devices. The host computer executes the software program and assigns a unique identification code to each of the peripheral devices.
In this embodiment the interface further incudes memory which stores the uniqe identification code, which is operatively connected to a corresponding microprocessor. The microprocessor utilizes the unique identification code to compare with an address recieved with data from the computer, to determine if it is the intended recipient of data transmitted by the computer. The microprocessor causes the corresponding peripheral device to execute the transmitted data if the unique identification code matches the transmitted address. The apperatus includes a plurality of such interfaces, being operatively connected in a daisy chain configuration to the interface input, such that the first peripheral input device is operatively connected to an interface input of a last interface of said daisy chain.